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2026-03-04fgraph: Do not call handlers direct when not using ftrace_opsSteven Rostedt1-1/+11
[ Upstream commit f4ff9f646a4d373f9e895c2f0073305da288bc0a ] The function graph tracer was modified to us the ftrace_ops of the function tracer. This simplified the code as well as allowed more features of the function graph tracer. Not all architectures were converted over as it required the implementation of HAVE_DYNAMIC_FTRACE_WITH_ARGS to implement. For those architectures, it still did it the old way where the function graph tracer handle was called by the function tracer trampoline. The handler then had to check the hash to see if the registered handlers wanted to be called by that function or not. In order to speed up the function graph tracer that used ftrace_ops, if only one callback was registered with function graph, it would call its function directly via a static call. Now, if the architecture does not support the use of using ftrace_ops and still has the ftrace function trampoline calling the function graph handler, then by doing a direct call it removes the check against the handler's hash (list of functions it wants callbacks to), and it may call that handler for functions that the handler did not request calls for. On 32bit x86, which does not support the ftrace_ops use with function graph tracer, it shows the issue: ~# trace-cmd start -p function -l schedule ~# trace-cmd show # tracer: function_graph # # CPU DURATION FUNCTION CALLS # | | | | | | | 2) * 11898.94 us | schedule(); 3) # 1783.041 us | schedule(); 1) | schedule() { ------------------------------------------ 1) bash-8369 => kworker-7669 ------------------------------------------ 1) | schedule() { ------------------------------------------ 1) kworker-7669 => bash-8369 ------------------------------------------ 1) + 97.004 us | } 1) | schedule() { [..] Now by starting the function tracer is another instance: ~# trace-cmd start -B foo -p function This causes the function graph tracer to trace all functions (because the function trace calls the function graph tracer for each on, and the function graph trace is doing a direct call): ~# trace-cmd show # tracer: function_graph # # CPU DURATION FUNCTION CALLS # | | | | | | | 1) 1.669 us | } /* preempt_count_sub */ 1) + 10.443 us | } /* _raw_spin_unlock_irqrestore */ 1) | tick_program_event() { 1) | clockevents_program_event() { 1) 1.044 us | ktime_get(); 1) 6.481 us | lapic_next_event(); 1) + 10.114 us | } 1) + 11.790 us | } 1) ! 181.223 us | } /* hrtimer_interrupt */ 1) ! 184.624 us | } /* __sysvec_apic_timer_interrupt */ 1) | irq_exit_rcu() { 1) 0.678 us | preempt_count_sub(); When it should still only be tracing the schedule() function. To fix this, add a macro FGRAPH_NO_DIRECT to be set to 0 when the architecture does not support function graph use of ftrace_ops, and set to 1 otherwise. Then use this macro to know to allow function graph tracer to call the handlers directly or not. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Mark Rutland <mark.rutland@arm.com> Link: https://patch.msgid.link/20260218104244.5f14dade@gandalf.local.home Fixes: cc60ee813b503 ("function_graph: Use static_call and branch to optimize entry function") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04function_graph: Restore direct mode when callbacks drop to oneShengming Hu1-1/+1
[ Upstream commit 53b2fae90ff01fede6520ca744ed5e8e366497ba ] When registering a second fgraph callback, direct path is disabled and array loop is used instead. When ftrace_graph_active falls back to one, we try to re-enable direct mode via ftrace_graph_enable_direct(true, ...). But ftrace_graph_enable_direct() incorrectly disables the static key rather than enabling it. This leaves fgraph_do_direct permanently off after first multi-callback transition, so direct fast mode is never restored. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260213142932519cuWSpEXeS4-UnCvNXnK2P@zte.com.cn Fixes: cc60ee813b503 ("function_graph: Use static_call and branch to optimize entry function") Signed-off-by: Shengming Hu <hu.shengming@zte.com.cn> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04fgraph: Replace fgraph_ret_regs with ftrace_regsMasami Hiramatsu (Google)1-12/+9
[ Upstream commit a3ed4157b7d89800a0008de0c9e46a438a5c3745 ] Use ftrace_regs instead of fgraph_ret_regs for tracing return value on function_graph tracer because of simplifying the callback interface. The CONFIG_HAVE_FUNCTION_GRAPH_RETVAL is also replaced by CONFIG_HAVE_FUNCTION_GRAPH_FREGS. Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Will Deacon <will@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Florent Revest <revest@chromium.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: bpf <bpf@vger.kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Alan Maguire <alan.maguire@oracle.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: x86@kernel.org Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/173518991508.391279.16635322774382197642.stgit@devnote2 Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Stable-dep-of: aea251799998 ("x86/fgraph,bpf: Switch kprobe_multi program stack unwind to hw_regs path") Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-08fgraph: Check ftrace_pids_enabled on registration for early filteringShengming Hu1-2/+7
commit 1650a1b6cb1ae6cb99bb4fce21b30ebdf9fc238e upstream. When registering ftrace_graph, check if ftrace_pids_enabled is active. If enabled, assign entryfunc to fgraph_pid_func to ensure filtering is performed before executing the saved original entry function. Cc: stable@vger.kernel.org Cc: <wang.yaxin@zte.com.cn> Cc: <mhiramat@kernel.org> Cc: <mark.rutland@arm.com> Cc: <mathieu.desnoyers@efficios.com> Cc: <zhang.run@zte.com.cn> Cc: <yang.yang29@zte.com.cn> Link: https://patch.msgid.link/20251126173331679XGVF98NLhyLJRdtNkVZ6w@zte.com.cn Fixes: df3ec5da6a1e7 ("function_graph: Add pid tracing back to function graph tracer") Signed-off-by: Shengming Hu <hu.shengming@zte.com.cn> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-08fgraph: Initialize ftrace_ops->private for function graph opsShengming Hu1-0/+1
commit b5d6d3f73d0bac4a7e3a061372f6da166fc6ee5c upstream. The ftrace_pids_enabled(op) check relies on op->private being properly initialized, but fgraph_ops's underlying ftrace_ops->private was left uninitialized. This caused ftrace_pids_enabled() to always return false, effectively disabling PID filtering for function graph tracing. Fix this by copying src_ops->private to dst_ops->private in fgraph_init_ops(), ensuring PID filter state is correctly propagated. Cc: stable@vger.kernel.org Cc: <wang.yaxin@zte.com.cn> Cc: <mhiramat@kernel.org> Cc: <mark.rutland@arm.com> Cc: <mathieu.desnoyers@efficios.com> Cc: <zhang.run@zte.com.cn> Cc: <yang.yang29@zte.com.cn> Fixes: c132be2c4fcc1 ("function_graph: Have the instances use their own ftrace_ops for filtering") Link: https://patch.msgid.link/20251126172926004y3hC8QyU4WFOjBkU_UxLC@zte.com.cn Signed-off-by: Shengming Hu <hu.shengming@zte.com.cn> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-19trace/fgraph: Fix error handlingGuenter Roeck1-1/+2
[ Upstream commit ab1396af7595e7d49a3850481b24d7fe7cbdfd31 ] Commit edede7a6dcd7 ("trace/fgraph: Fix the warning caused by missing unregister notifier") added a call to unregister the PM notifier if register_ftrace_graph() failed. It does so unconditionally. However, the PM notifier is only registered with the first call to register_ftrace_graph(). If the first registration was successful and a subsequent registration failed, the notifier is now unregistered even if ftrace graphs are still registered. Fix the problem by only unregistering the PM notifier during error handling if there are no active fgraph registrations. Fixes: edede7a6dcd7 ("trace/fgraph: Fix the warning caused by missing unregister notifier") Closes: https://lore.kernel.org/all/63b0ba5a-a928-438e-84f9-93028dd72e54@roeck-us.net/ Cc: Ye Weihua <yeweihua4@huawei.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20250906050618.2634078-1-linux@roeck-us.net Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-09-04trace/fgraph: Fix the warning caused by missing unregister notifierYe Weihua1-0/+1
[ Upstream commit edede7a6dcd7435395cf757d053974aaab6ab1c2 ] This warning was triggered during testing on v6.16: notifier callback ftrace_suspend_notifier_call already registered WARNING: CPU: 2 PID: 86 at kernel/notifier.c:23 notifier_chain_register+0x44/0xb0 ... Call Trace: <TASK> blocking_notifier_chain_register+0x34/0x60 register_ftrace_graph+0x330/0x410 ftrace_profile_write+0x1e9/0x340 vfs_write+0xf8/0x420 ? filp_flush+0x8a/0xa0 ? filp_close+0x1f/0x30 ? do_dup2+0xaf/0x160 ksys_write+0x65/0xe0 do_syscall_64+0xa4/0x260 entry_SYSCALL_64_after_hwframe+0x77/0x7f When writing to the function_profile_enabled interface, the notifier was not unregistered after start_graph_tracing failed, causing a warning the next time function_profile_enabled was written. Fixed by adding unregister_pm_notifier in the exception path. Link: https://lore.kernel.org/20250818073332.3890629-1-yeweihua4@huawei.com Fixes: 4a2b8dda3f870 ("tracing/function-graph-tracer: fix a regression while suspend to disk") Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Ye Weihua <yeweihua4@huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-09fgraph: Add READ_ONCE() when accessing fgraph_array[]Zilin Guan1-1/+1
commit d65474033740ded0a4fe9a097fce72328655b41d upstream. In __ftrace_return_to_handler(), a loop iterates over the fgraph_array[] elements, which are fgraph_ops. The loop checks if an element is a fgraph_stub to prevent using a fgraph_stub afterward. However, if the compiler reloads fgraph_array[] after this check, it might race with an update to fgraph_array[] that introduces a fgraph_stub. This could result in the stub being processed, but the stub contains a null "func_hash" field, leading to a NULL pointer dereference. To ensure that the gops compared against the fgraph_stub matches the gops processed later, add a READ_ONCE(). A similar patch appears in commit 63a8dfb ("function_graph: Add READ_ONCE() when accessing fgraph_array[]"). Cc: stable@vger.kernel.org Fixes: 37238abe3cb47 ("ftrace/function_graph: Pass fgraph_ops to function graph callbacks") Link: https://lore.kernel.org/20241231113731.277668-1-zilin@seu.edu.cn Signed-off-by: Zilin Guan <zilin@seu.edu.cn> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-27fgraph: Still initialize idle shadow stacks when startingSteven Rostedt1-1/+7
commit cc252bb592638e0f7aea40d580186c36d89526b8 upstream. A bug was discovered where the idle shadow stacks were not initialized for offline CPUs when starting function graph tracer, and when they came online they were not traced due to the missing shadow stack. To fix this, the idle task shadow stack initialization was moved to using the CPU hotplug callbacks. But it removed the initialization when the function graph was enabled. The problem here is that the hotplug callbacks are called when the CPUs come online, but the idle shadow stack initialization only happens if function graph is currently active. This caused the online CPUs to not get their shadow stack initialized. The idle shadow stack initialization still needs to be done when the function graph is registered, as they will not be allocated if function graph is not registered. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20241211135335.094ba282@batman.local.home Fixes: 2c02f7375e65 ("fgraph: Use CPU hotplug mechanism to initialize idle shadow stacks") Reported-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Linus Walleij <linus.walleij@linaro.org> Closes: https://lore.kernel.org/all/CACRpkdaTBrHwRbbrphVy-=SeDz6MSsXhTKypOtLrTQ+DgGAOcQ@mail.gmail.com/ Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-24fgraph: Change the name of cpuhp state to "fgraph:online"Steven Rostedt1-1/+1
The cpuhp state name given to cpuhp_setup_state() is "fgraph_idle_init" which doesn't really conform to the names that are used for cpu hotplug setups. Instead rename it to "fgraph:online" to be in line with other states. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/20241024222944.473d88c5@rorschach.local.home Suggested-by: Masami Hiramatsu <mhiramat@kernel.org> Fixes: 2c02f7375e658 ("fgraph: Use CPU hotplug mechanism to initialize idle shadow stacks") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-24fgraph: Fix missing unlock in register_ftrace_graph()Li Huafei1-7/+3
Use guard(mutex)() to acquire and automatically release ftrace_lock, fixing the issue of not unlocking when calling cpuhp_setup_state() fails. Fixes smatch warning: kernel/trace/fgraph.c:1317 register_ftrace_graph() warn: inconsistent returns '&ftrace_lock'. Link: https://lore.kernel.org/20241024155917.1019580-1-lihuafei1@huawei.com Fixes: 2c02f7375e65 ("fgraph: Use CPU hotplug mechanism to initialize idle shadow stacks") Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: https://lore.kernel.org/r/202410220121.wxg0olfd-lkp@intel.com/ Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Li Huafei <lihuafei1@huawei.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-18fgraph: Allocate ret_stack_list with proper sizeSteven Rostedt1-1/+2
The ret_stack_list is an array of ret_stack shadow stacks for the function graph usage. When the first function graph is enabled, all tasks in the system get a shadow stack. The ret_stack_list is a 32 element array of pointers to these shadow stacks. It allocates the shadow stack in batches (32 stacks at a time), assigns them to running tasks, and continues until all tasks are covered. When the function graph shadow stack changed from an array of ftrace_ret_stack structures to an array of longs, the allocation of ret_stack_list went from allocating an array of 32 elements to just a block defined by SHADOW_STACK_SIZE. Luckily, that's defined as PAGE_SIZE and is much more than enough to hold 32 pointers. But it is way overkill for the amount needed to allocate. Change the allocation of ret_stack_list back to a kcalloc() of FTRACE_RETSTACK_ALLOC_SIZE pointers. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20241018215212.23f13f40@rorschach Fixes: 42675b723b484 ("function_graph: Convert ret_stack to a series of longs") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-18fgraph: Use CPU hotplug mechanism to initialize idle shadow stacksSteven Rostedt1-7/+21
The function graph infrastructure allocates a shadow stack for every task when enabled. This includes the idle tasks. The first time the function graph is invoked, the shadow stacks are created and never freed until the task exits. This includes the idle tasks. Only the idle tasks that were for online CPUs had their shadow stacks created when function graph tracing started. If function graph tracing is enabled and a CPU comes online, the idle task representing that CPU will not have its shadow stack created, and all function graph tracing for that idle task will be silently dropped. Instead, use the CPU hotplug mechanism to allocate the idle shadow stacks. This will include idle tasks for CPUs that come online during tracing. This issue can be reproduced by: # cd /sys/kernel/tracing # echo 0 > /sys/devices/system/cpu/cpu1/online # echo 0 > set_ftrace_pid # echo function_graph > current_tracer # echo 1 > options/funcgraph-proc # echo 1 > /sys/devices/system/cpu/cpu1 # grep '<idle>' per_cpu/cpu1/trace | head Before, nothing would show up. After: 1) <idle>-0 | 0.811 us | __enqueue_entity(); 1) <idle>-0 | 5.626 us | } /* enqueue_entity */ 1) <idle>-0 | | dl_server_update_idle_time() { 1) <idle>-0 | | dl_scaled_delta_exec() { 1) <idle>-0 | 0.450 us | arch_scale_cpu_capacity(); 1) <idle>-0 | 1.242 us | } 1) <idle>-0 | 1.908 us | } 1) <idle>-0 | | dl_server_start() { 1) <idle>-0 | | enqueue_dl_entity() { 1) <idle>-0 | | task_contending() { Note, if tracing stops and restarts, the old way would then initialize the onlined CPUs. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/20241018214300.6df82178@rorschach Fixes: 868baf07b1a25 ("ftrace: Fix memory leak with function graph and cpu hotplug") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-21tracing: fgraph: Fix to add new fgraph_ops to array after ↵Masami Hiramatsu (Google)1-13/+18
ftrace_startup_subops() Since the register_ftrace_graph() assigns a new fgraph_ops to fgraph_array before registring it by ftrace_startup_subops(), the new fgraph_ops can be used in function_graph_enter(). In most cases, it is still OK because those fgraph_ops's hashtable is already initialized by ftrace_set_filter*() etc. But if a user registers a new fgraph_ops which does not initialize the hash list, ftrace_ops_test() in function_graph_enter() causes a NULL pointer dereference BUG because fgraph_ops->ops.func_hash is NULL. This can be reproduced by the below commands because function profiler's fgraph_ops does not initialize the hash list; # cd /sys/kernel/tracing # echo function_graph > current_tracer # echo 1 > function_profile_enabled To fix this problem, add a new fgraph_ops to fgraph_array after ftrace_startup_subops(). Thus, until the new fgraph_ops is initialized, we will see fgraph_stub on the corresponding fgraph_array entry. Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Florent Revest <revest@chromium.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: bpf <bpf@vger.kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Alan Maguire <alan.maguire@oracle.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/172398528350.293426.8347220120333730248.stgit@devnote2 Fixes: c132be2c4fcc ("function_graph: Have the instances use their own ftrace_ops for filtering") Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-08-07function_graph: Fix the ret_stack used by ftrace_graph_ret_addr()Petr Pavlu1-1/+1
When ftrace_graph_ret_addr() is invoked to convert a found stack return address to its original value, the function can end up producing the following crash: [ 95.442712] BUG: kernel NULL pointer dereference, address: 0000000000000028 [ 95.442720] #PF: supervisor read access in kernel mode [ 95.442724] #PF: error_code(0x0000) - not-present page [ 95.442727] PGD 0 P4D 0- [ 95.442731] Oops: Oops: 0000 [#1] PREEMPT SMP PTI [ 95.442736] CPU: 1 UID: 0 PID: 2214 Comm: insmod Kdump: loaded Tainted: G OE K 6.11.0-rc1-default #1 67c62a3b3720562f7e7db5f11c1fdb40b7a2857c [ 95.442747] Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE, [K]=LIVEPATCH [ 95.442750] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014 [ 95.442754] RIP: 0010:ftrace_graph_ret_addr+0x42/0xc0 [ 95.442766] Code: [...] [ 95.442773] RSP: 0018:ffff979b80ff7718 EFLAGS: 00010006 [ 95.442776] RAX: ffffffff8ca99b10 RBX: ffff979b80ff7760 RCX: ffff979b80167dc0 [ 95.442780] RDX: ffffffff8ca99b10 RSI: ffff979b80ff7790 RDI: 0000000000000005 [ 95.442783] RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000 [ 95.442786] R10: 0000000000000005 R11: 0000000000000000 R12: ffffffff8e9491e0 [ 95.442790] R13: ffffffff8d6f70f0 R14: ffff979b80167da8 R15: ffff979b80167dc8 [ 95.442793] FS: 00007fbf83895740(0000) GS:ffff8a0afdd00000(0000) knlGS:0000000000000000 [ 95.442797] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 95.442800] CR2: 0000000000000028 CR3: 0000000005070002 CR4: 0000000000370ef0 [ 95.442806] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 95.442809] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 95.442816] Call Trace: [ 95.442823] <TASK> [ 95.442896] unwind_next_frame+0x20d/0x830 [ 95.442905] arch_stack_walk_reliable+0x94/0xe0 [ 95.442917] stack_trace_save_tsk_reliable+0x7d/0xe0 [ 95.442922] klp_check_and_switch_task+0x55/0x1a0 [ 95.442931] task_call_func+0xd3/0xe0 [ 95.442938] klp_try_switch_task.part.5+0x37/0x150 [ 95.442942] klp_try_complete_transition+0x79/0x2d0 [ 95.442947] klp_enable_patch+0x4db/0x890 [ 95.442960] do_one_initcall+0x41/0x2e0 [ 95.442968] do_init_module+0x60/0x220 [ 95.442975] load_module+0x1ebf/0x1fb0 [ 95.443004] init_module_from_file+0x88/0xc0 [ 95.443010] idempotent_init_module+0x190/0x240 [ 95.443015] __x64_sys_finit_module+0x5b/0xc0 [ 95.443019] do_syscall_64+0x74/0x160 [ 95.443232] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 95.443236] RIP: 0033:0x7fbf82f2c709 [ 95.443241] Code: [...] [ 95.443247] RSP: 002b:00007fffd5ea3b88 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 95.443253] RAX: ffffffffffffffda RBX: 000056359c48e750 RCX: 00007fbf82f2c709 [ 95.443257] RDX: 0000000000000000 RSI: 000056356ed4efc5 RDI: 0000000000000003 [ 95.443260] RBP: 000056356ed4efc5 R08: 0000000000000000 R09: 00007fffd5ea3c10 [ 95.443263] R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000 [ 95.443267] R13: 000056359c48e6f0 R14: 0000000000000000 R15: 0000000000000000 [ 95.443272] </TASK> [ 95.443274] Modules linked in: [...] [ 95.443385] Unloaded tainted modules: intel_uncore_frequency(E):1 isst_if_common(E):1 skx_edac(E):1 [ 95.443414] CR2: 0000000000000028 The bug can be reproduced with kselftests: cd linux/tools/testing/selftests make TARGETS='ftrace livepatch' (cd ftrace; ./ftracetest test.d/ftrace/fgraph-filter.tc) (cd livepatch; ./test-livepatch.sh) The problem is that ftrace_graph_ret_addr() is supposed to operate on the ret_stack of a selected task but wrongly accesses the ret_stack of the current task. Specifically, the above NULL dereference occurs when task->curr_ret_stack is non-zero, but current->ret_stack is NULL. Correct ftrace_graph_ret_addr() to work with the right ret_stack. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reported-by: Miroslav Benes <mbenes@suse.cz> Link: https://lore.kernel.org/20240803131211.17255-1-petr.pavlu@suse.com Fixes: 7aa1eaef9f42 ("function_graph: Allow multiple users to attach to function graph") Signed-off-by: Petr Pavlu <petr.pavlu@suse.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-14function_graph: Add READ_ONCE() when accessing fgraph_array[]Steven Rostedt (Google)1-1/+1
In function_graph_enter() there's a loop that looks at fgraph_array[] elements which are fgraph_ops. It first tests if it is a fgraph_stub op, and if so skips it, as that's just there as a place holder. Then it checks the fgraph_ops filters to see if the ops wants to trace the current function. But if the compiler reloads the fgraph_array[] after the check against fgraph_stub, it could race with the fgraph_array[] being updated with the fgraph_stub. That would cause the stub to be processed. But the stub has a null "func_hash" field which will cause a NULL pointer dereference. Add a READ_ONCE() so that the gops that is compared against the fgraph_stub is also the gops that is processed later. Link: https://lore.kernel.org/all/CA+G9fYsSVJQZH=nM=1cjTc94PgSnMF9y65BnOv6XSoCG_b6wmw@mail.gmail.com/ Link: https://lore.kernel.org/linux-trace-kernel/20240613095223.1f07e3a4@rorschach.local.home Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Fixes: cc60ee813b503 ("function_graph: Use static_call and branch to optimize entry function") Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-06-11function_graph: Everyone uses HAVE_FUNCTION_GRAPH_RET_ADDR_PTR, remove itSteven Rostedt (Google)1-34/+1
All architectures that implement function graph also implements HAVE_FUNCTION_GRAPH_RET_ADDR_PTR. Remove it, as it is no longer a differentiator. Link: https://lore.kernel.org/linux-trace-kernel/20240611031737.982047614@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Guo Ren <guoren@kernel.org> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-11function_graph: Fix up ftrace_graph_ret_addr()Steven Rostedt (Google)1-8/+20
Yang Li sent a patch to fix the kerneldoc of ftrace_graph_ret_addr(). While reviewing it, I realized that the comments in the entire function header needed a rewrite. When doing that, I realized that @idx parameter was being ignored. Every time this was called by the unwinder, it would start the loop at the top of the shadow stack and look for the matching stack pointer. When it found it, it would return it. When the unwinder asked for the next function, it would search from the beginning again. In reality, it should start from where it left off. That was the reason for the @idx parameter in the first place. The first time the unwinder calls this function, the @idx pointer would contain zero. That would mean to start from the top of the stack. The function was supposed to update the @idx with the index where it found the return address, so that the next time the unwinder calls this function it doesn't have to search through the previous addresses it found (making it O(n^2)!). This speeds up the unwinder's use of ftrace_graph_ret_addr() by an order of magnitude. Link: https://lore.kernel.org/linux-trace-kernel/20240610181746.656e3759@gandalf.local.home/ Link: https://lore.kernel.org/linux-trace-kernel/20240611031737.821995106@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Guo Ren <guoren@kernel.org> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Reported-by: Yang Li <yang.lee@linux.alibaba.com> Fixes: 7aa1eaef9f428 ("function_graph: Allow multiple users to attach to function graph") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-10function_graph: Make fgraph_update_pid_func() a stub for !DYNAMIC_FTRACESteven Rostedt (Google)1-2/+2
When CONFIG_DYNAMIC_FTRACE is not set, the function fgraph_update_pid_func() doesn't do anything. Currently, most of its logic is within a "#ifdef CONFIG_DYNAMIC_FTRACE" block, but its variables were declared outside that, and when DYNAMIC_FTRACE is not set, it produces unused variable warnings. Instead, just place it (and the helper function fgraph_pid_func()) within the #ifdef block and have the header file use a empty stub function for when DYNAMIC_FTRACE is not defined. Link: https://lore.kernel.org/linux-trace-kernel/20240607094833.6a787d73@rorschach.local.home Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202406071806.BRjaC5FF-lkp@intel.com/ Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06fgraph: Remove some unused functionsJiapeng Chong1-13/+0
These functions are defined in the fgraph.c file, but not called elsewhere, so delete these unused functions. kernel/trace/fgraph.c:273:1: warning: unused function 'set_bitmap_bits'. kernel/trace/fgraph.c:259:19: warning: unused function 'get_fgraph_type'. Link: https://lore.kernel.org/linux-trace-kernel/20240606021053.27783-1-jiapeng.chong@linux.alibaba.com Reported-by: Abaci Robot <abaci@linux.alibaba.com> Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=9289 Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06function_graph: Do not update pid func if CONFIG_DYNAMIC_FTRACE not enabledSteven Rostedt (Google)1-0/+2
The ftrace subops is only defined if CONFIG_DYNAMIC_FTRACE is enabled. If it is not, function tracing is extremely limited, and the subops in the ftrace_ops structure is not defined (and will fail to compile). If DYNAMIC_FTRACE is not enabled, then function graph filtering will not work (as it shouldn't). Link: https://lore.kernel.org/linux-trace-kernel/20240605202709.096020676@goodmis.org Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Fixes: df3ec5da6a1e7 ("function_graph: Add pid tracing back to function graph tracer") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202406051855.9VIYXbTB-lkp@intel.com/ Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-06function_graph: Make fgraph_do_direct static key staticSteven Rostedt (Google)1-1/+1
The static branch key "fgraph_do_direct" was not declared static but is only used in one file. Change it to a static variable. Link: https://lore.kernel.org/linux-trace-kernel/20240605202708.936515302@goodmis.org Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Fixes: cc60ee813b503 ("function_graph: Use static_call and branch to optimize entry function") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202406051711.dS1sQZ9n-lkp@intel.com/ Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04function_graph: Use static_call and branch to optimize return functionSteven Rostedt (Google)1-5/+18
In most cases function graph is used by a single user. Instead of calling a loop to call function graph callbacks in this case, call the function return callback directly. Use the static_key that is set when the function graph tracer has less than 2 callbacks registered. It will do the direct call in that case, and will do the loop over all callers when there are 2 or more callbacks registered. Link: https://lore.kernel.org/linux-trace-kernel/20240603190824.921460797@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Florent Revest <revest@chromium.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: bpf <bpf@vger.kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Alan Maguire <alan.maguire@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Guo Ren <guoren@kernel.org> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04function_graph: Use static_call and branch to optimize entry functionSteven Rostedt (Google)1-11/+66
In most cases function graph is used by a single user. Instead of calling a loop to call function graph callbacks in this case, call the function entry callback directly. Add a static_key that will be used to set the function graph logic to either do the loop (when more than one callback is registered) or to call the callback directly if there is only one registered callback. Link: https://lore.kernel.org/linux-trace-kernel/20240603190824.766858241@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Florent Revest <revest@chromium.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: bpf <bpf@vger.kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Alan Maguire <alan.maguire@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Guo Ren <guoren@kernel.org> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04function_graph: Use bitmask to loop on fgraph entrySteven Rostedt (Google)1-1/+7
Instead of looping through all the elements of fgraph_array[] to see if there's an gops attached to one and then calling its gops->func(). Create a fgraph_array_bitmask that sets bits when an index in the array is reserved (via the simple lru algorithm). Then only the bits set in this bitmask needs to be looked at where only elements in the array that have ops registered need to be looked at. Note, we do not care about races. If a bit is set before the gops is assigned, it only wastes time looking at the element and ignoring it (as it did before this bitmask is added). Link: https://lore.kernel.org/linux-trace-kernel/20240603190824.604448781@goodmis.org Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Florent Revest <revest@chromium.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: bpf <bpf@vger.kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Alan Maguire <alan.maguire@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Guo Ren <guoren@kernel.org> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04function_graph: Use for_each_set_bit() in __ftrace_return_to_handler()Steven Rostedt (Google)1-3/+2
Instead of iterating through the entire fgraph_array[] and seeing if one of the bitmap bits are set to know to call the array's retfunc() function, use for_each_set_bit() on the bitmap itself. This will only iterate for the number of set bits. Link: https://lore.kernel.org/linux-trace-kernel/20240603190824.447448026@goodmis.org Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Florent Revest <revest@chromium.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: bpf <bpf@vger.kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Alan Maguire <alan.maguire@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Guo Ren <guoren@kernel.org> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04function_graph: Implement fgraph_reserve_data() and fgraph_retrieve_data()Steven Rostedt (VMware)1-8/+183
Added functions that can be called by a fgraph_ops entryfunc and retfunc to store state between the entry of the function being traced to the exit of the same function. The fgraph_ops entryfunc() may call fgraph_reserve_data() to store up to 32 words onto the task's shadow ret_stack and this then can be retrieved by fgraph_retrieve_data() called by the corresponding retfunc(). Co-developed with Masami Hiramatsu: Link: https://lore.kernel.org/linux-trace-kernel/171509109089.162236.11372474169781184034.stgit@devnote2 Link: https://lore.kernel.org/linux-trace-kernel/20240603190823.959703050@goodmis.org Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Florent Revest <revest@chromium.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: bpf <bpf@vger.kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Alan Maguire <alan.maguire@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Guo Ren <guoren@kernel.org> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04function_graph: Add "task variables" per task for fgraph_opsSteven Rostedt (VMware)1-1/+73
Add a "task variables" array on the tasks shadow ret_stack that is the size of longs for each possible registered fgraph_ops. That's a total of 16, taking up 8 * 16 = 128 bytes (out of a page size 4k). This will allow for fgraph_ops to do specific features on a per task basis having a way to maintain state for each task. Co-developed with Masami Hiramatsu: Link: https://lore.kernel.org/linux-trace-kernel/171509104383.162236.12239656156685718550.stgit@devnote2 Link: https://lore.kernel.org/linux-trace-kernel/20240603190823.308806126@goodmis.org Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Florent Revest <revest@chromium.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: bpf <bpf@vger.kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Alan Maguire <alan.maguire@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Guo Ren <guoren@kernel.org> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04function_graph: Use a simple LRU for fgraph_array index numberMasami Hiramatsu (Google)1-21/+50
Since the fgraph_array index is used for the bitmap on the shadow stack, it may leave some entries after a function_graph instance is removed. Thus if another instance reuses the fgraph_array index soon after releasing it, the fgraph may confuse to call the newer callback for the entries which are pushed by the older instance. To avoid reusing the fgraph_array index soon after releasing, introduce a simple LRU table for managing the index number. This will reduce the possibility of this confusion. Link: https://lore.kernel.org/linux-trace-kernel/171509103267.162236.6885097397289135378.stgit@devnote2 Link: https://lore.kernel.org/linux-trace-kernel/20240603190823.147421545@goodmis.org Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Florent Revest <revest@chromium.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: bpf <bpf@vger.kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Alan Maguire <alan.maguire@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Guo Ren <guoren@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04function_graph: Add pid tracing back to function graph tracerSteven Rostedt (Google)1-0/+40
Now that the function_graph has a main callback that handles the function graph subops tracing, it no longer honors the pid filtering of ftrace. Add back this logic in the function_graph code to update the gops callback for the entry function to test if it should trace the current task or not. Link: https://lore.kernel.org/linux-trace-kernel/20240603190822.991720703@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Florent Revest <revest@chromium.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: bpf <bpf@vger.kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Alan Maguire <alan.maguire@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Guo Ren <guoren@kernel.org> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-04function_graph: Have the instances use their own ftrace_ops for filteringSteven Rostedt (VMware)1-30</